The filling compound of this invention is for use in communication cables and has been developed with a solidification temperature low enough so that high pair count small conductor cores can be filled fully with the liquid filling process. The soft and pliable filling compound will not drip at temperatures up to 90.degree.. The addition of from 5 to 10 or more parts by weight of polyethylene compound to the base material provides the desired characteristics for the filling compound.
The base material is a paraffinic type oil having a Saybolt Universal viscosity of approximately 2500-3500 seconds at 37.8.degree. C., the paraffinic oil comprising 100 parts of the filler material.
Another important consideration in the formulation of the filler compound is to avoid having it permeate into the cells of foam skin or all foam insulation. This characteristic was obtained by selecting the specific high viscosity base oil and by increasing the surface tension of the compound with the addition of 1 to 2 parts or more of butyl rubber, or similar material. The new filling compound reduces the swelling of the insulation and less extraction of copper inhibitor and antioxidants thereby increasing the life of the insulation in the pedestal environment. The additive for increasing surface tension provides the desired tackiness and good adhesion of the filler material to the cable components.